Apparatus for continuously decomposing hydrocarbon in a heating medium bath

ABSTRACT

APPARATUS FOR CONTINUOUSLY DECOMPOSING HYDROCARBON GASES IN A HEATED BATH IN WHICH THE APPARATUS IS DIVIDED INTO A HEATING CHAMBER AND A DECOMPOSING CHAMBER RESPECTIVELY. THE LIQUID MEDIUM OF THE BATH IS HEATED IN THE HEATING CHAMBER BY BLOWING COMBUSTION GAS INTO THE BATH, THE COOLED GAS IS SEPARATED AT THE TOP OF THE HEATING CHAMBER AND THE HEATED MEDIUM IS CAUSED TO OVERFLOW AND IS DIRECTED TO THE BOTTOM OF THE DECOMPOSITION CHAMBER. THE HYDROCARBON IS INTRODUCED INTO THE LIQUID IN THE DECOMPOSITION CHAMBER AND IS DISCHARGED AT THE TOP OF THE CHAMBER AND THE LIQUID MEDIUM IS CAUSED TO OVERFLOW INTO A PASSAGEWAY OPENING INTO THE BOTTOM OF THE HEATING CHAMBER SO THAT THE LIQUID HEATING MEDIUM IS CAUSED TO CIRCULATE CONTINUOUSLY FROM THE HEATING CHAMBER THROUGH THE DECOMPOSITION CHAMBER AND BACK TO THE HEATING CHAMBER WITHOUT PERMITTING CO-MINGLING OF HE COMBUSTION GASES USED FOR HEATING THE MEDIUM AND THE HYDROCARBON WHICH IS DECOMPOSED IN THE DECOMPOSITION CHAMBER.

April 24, 1973 FUJIO os A ET AL 3,729,297

APPARATUS FOR CONTINUOUSLY DECOMPOSING HYDROCARBON IN A HEATING MEDIUM BATH llied Nov. 25, 1970 3 Sheets-Sheet 2 FIG.3

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April 24, 1973 FUJIO YOSHIDA ET AL 3,729,297.

APPARATUS FOR CONTINUOUSLY DECOMPOSING HYDROCARBON IN A HEATING MEDIUM BATH IllGd NOV. 25, 1970 3 Sheets-Sheet 5 United States Patent APPARATUS FOR CONTINUOUSLY DECOMPOS- INAG HYDROCARBON IN A HEATING MEDIUM B TH Fujio Yoshida and Kagesumi Akamatsu, Okayama, and Nobito Hara, Yamaguchi, Japan, assignors to Mitsui Shipbuilding and Engineering Co. Ltd., and Mitsui Petrochemical Industries Limited, both of Tokyo,

Japan Filed Nov. 25, 1970, Ser. No. 92,662 Claims priority, application Japan, Nov. 29, 1969, 44/95,471 Int. Cl. C01b 2/28 US. Cl. 48-92 2 Claims ABSTRACT OF THE DISCLOSURE Apparatus for continuously decomposing hydrocarbon gases in a heated bath in which the apparatus is divided into a heating chamber and a decomposing chamber respectively. The liquid medium of the bath is heated in the heating chamber by blowing combustion gas into the bath. The cooled gas is separated at the top of the heating chamber and the heated medium is caused to overflow and is directed to the bottom of the decomposition chambet. The hydrocarbon is introduced into the liquid in the decomposition chamber and is discharged at the top of the chamber and the liquid medium is caused to overflow into a passageway opening into the bottom of the heating chamber so that the liquid heating medium is caused to circulate continuously from the heating chamber through the decomposition chamber and back to the heating chamber without permitting co-mingling of the combustion gases used for heating the medium and the hydrocarbon which is decomposed in the decomposition chamber.

The present invention relates to a method and apparatus for decomposing hydrocarbon, and more particularly to a method in which molten metal or a fused salt is employed as a heating medium and hydrocarbon such as propane, naphtha, crude petroleum, etc. is continuously introduced into the heating medium and the hydrocarbon is decomposed to obtain olefines of low molecular weight such as acetylene, ethylene, propylene, etc.

Such a method and an apparatus for decomposition have been known, and, in accordance with the method, it is not necessary to construct a heating surface with a high quality material of good anti-corrosiveness, because of hydrocarbon being directly heated without any trouble such as corrosion. The apparatus can be made compact owing to the great amount of heat transfer per unit volume.

There are, however, many problems in heat exchange which is performed by movement and circulation of a heating medium, for example molten metal, and in separation of molten metal from the decomposed product.

The present inevntion is directed to solve such problems. The method according to the present invention, uses a gas lift elfect produced by blowing a hydrocarbon gas as a starting material into a decomposition chamber and a gas lift effect produced by blowing a combustion gas into a heating chamber of a heating medium, so that the heating medium is continuously circulated to decompose hydrocarbon or to effect a chemical reaction of hydrocarbon.

The apparatus according to the present invention, is characterized in that heating chamber and a decomposition chamber are provided in separation by a partition wall of a heat resisting material so as not to mix a'combustion gas and a decomposition gas, and these chambers are respectively divided into a gas blow portion and an overflow portion, the overflow portion of the heating 3,729,297 Patented Apr. 24, 1973 chamber and the raw gas blow portion of the decomposition chamber are connected through a connecting passage provided at the bottom part thereof, and the overflow portion of the decomposition chamber and the combustion gas blow portion of the heating chamber are also connected through a same passage as said passage.

The depth of the heating medium stocked and circulated in a bath can be designed as desired and by the temperature may be selected corresponding to the kind of raw hydrocarbon to be decomposed. The hydrocarbon material is previously heated and blowed in a gaseous condition into the molten metal of the decomposition chamber. The raw gas comes vehemently into contact with the hot molten metal and quickly heated to be decomposed. The flow out velocity of the blown gas or the decomposed gas from the decomposition chamber must be decided in such a value that the heating medium is not entrained on the gas but the decomposed gas does not stay in the decomposition chamber for so long a time as to bring a chemical reaction.

In the decomposition chamber, the heating medium includes foams of the decomposed gas so that the gravity of the heating medium is decreased and the liquid level is raised, which is termed gas lift eflect. The heating medium is separated from the decomposed hydrocarbon gas on its liquid surface and flown over the partition wall. The overflown heating medium falls down in the overflow portion and enters the lower part of the heating chamber through the connecting passage at the bottom part. The calories, taken away in the decomposition chamber, are replenished by a hot combustion gas in the heating chamber. In this case it is desirable that the combustion gas contains a small amount of air lest the heating medium is oxidized. The gas lift effect produced in the heating chamber by blowing of the combustion gas, makes the heating medium overflow from the heating portion to the overflow portion in the same manner as described as to the decomposition chamber. The heating medium is then flowed into the decomposition chamber through the passage of the bottom portion.

The present invention will be more fully set forth referring to the accompanying drawings, in which:

FIG. 1 is a vertical section view, showing an embodiment of an apparatus for decomposing hydrocarbon according to the present invention;

FIG. 2 is a plan view of FIG. 1 of which top portion is removed;

FIG. 3 is a plan view showing another embodiment, in which decomposition chambers are provided on both sides of a heating chamber;

FIG. 4 is a sectional view showing the right side of the same, taken along A-A of FIG. 3 and the left side, taken along B-B of FIG. 3;

FIG. 5 is a plan view showing further embodiment in which the apparatus is constructed in a circular shape; and

FIG. 6 is an elevational view showing the right side of the same, taken along E-E of FIG. 5, and the left side, taken along DD of FIG. 5.

As to the apparatus shown in FIGS. 1 and 2, the apparatus comprises the main body C for a bath, consisting of a shell 1 of steel plates reinforced by shape steel, a lining layer 2 of heat insulating bricks, and inner heat insulating bricks 3. A downardly extended partition wall 4 is provided at the center of the main body C to divide the chamber of the body into a decomposition chamber 14 and a heating chamber 15. Connecting passages 12 and 13 are also arranged between the lower end of the partition wall 4 and the botom part 11 of the main body C. An upwardly extending partition wall, namely, an overflow weir 5 is provided in the decomposition chamber 14 to divide the decomposition chamber 14 into a gas blowing portion 16 and an overflow portion 17. A similar partition wall, namely an overflow weir 6 is also provided in the heating chamber 15 to partition a combustion gas blowing portion 18 and an overflow portion 19. The overflow portion 17 and 19 are alternately arranged as shown in FIG. 2, and the overflow portion is connected with the blowing portion 18 through a connecting passage 12 at the lower part of the overflow portion 19. The overflow portion 19 is connected with the blowing portion 16 through a connecting passage 13 at the lower part of the overflow portion 17. The portion 16, into which gas is blowed to be decomposed, is provided with a suitable number of gas blowing pipes 7, and the portion 18, into which a combustion gas is blowed, is similarly provided with a suitable number of gas blowing pipes 9. And further, outlet pipes 8 for a decomposed gas are installed in the upper part of the decomposition chamber 14, and outlet pipes 10 for a combustion gas, also in the upper part of the heating chamber 15.

In operation, a combustion gas is blown into the combustion gas pipes 9 and a hydrocarbon gas to be decomposed is blown into the decomposition gas pipes 7. The gas flows out with comparative uniformity from tiny holes of the pipe 7. The hydrocarbon gas blown into a heating medium, for example, molten metal, preferably molten lead, is heated by the molten metal to be decomposed. At the same time, the molten metal in the blowing portion 16 flows upwards by the foams from the decomposition gas pipe 7, and the liquid level L1 becomes above the top of the overflow weir 5. Thus, the molten metal flows into the overflow portion 17. On the other hand, the decomposed gas is taken out from the outlet pipe 8. At that time, the decomposed gas is separated from the splashes of the molten metal in the space of the upper part of the decomposition chamber 14, so that the molten metal does not get away from the outlet pipe 8.

The molten metal in the overflow portion 17 flows through the connecting passage 12 of the lower portion into the portion 18. Combustion gas is blowed into the portion 18 through the combustion gas pipe 9, thus the molten metal is heated by the combustion gas. Further, the molten metal in the combustion gas blowing portion 18 overflows to the overflow portion 19, since the liquid surface L2 being raised up in the same maner as shown in the decomposition chamber. On the other hand, the combustion gas is exhausted from the outlet pipe 10. The molten metal of the overflow portion 19 flows into the gas blowing portion 16 through the other connecting passage 13 provided adjacent to the connecting passage 12. Thus, the above mentioned movement is again repeated. That is, the molten metal is circulated in a line of 16 17 12 18 19 13 16, and during the circulation, performs the operation for decomposition of gas.

The apparatus shown in FIGS. 3 and 4 is provided with decomposition chambers 14 arranged on both sides of a heating chamber 15, and which is substantially the same as that, shown in FIGS. 1 and 2. Accordingly, the corresponding parts are indicated with the same reference numbers. In this example, the molten metal is circulated in the same manner as described in the above embodiment.

The embodiment in FIGS. 5 and 6 shows an example of such a construction that decomposition chambers 14 are circularly arranged around a heating chamber 15, and is substantially the same to the embodiment of FIGS. 1 and 2. Accordingly, the corresponding parts are shown with the same reference numbers. In this embodiment, an overflow portion 19 is provided around a circular portion 18 into which combustion gas is blowed. An overflow portion .17 and a portion, into which gas is blowed to be decomposed, are constructed in the decomposition 4 chamber 14 around the overflow portion 19. In the illustrated embodiment, four combustion gas blowing pipes 7 are arranged as being separated as the angle of and the connecting passages 12 and 13 are respectively placed at four points in order to make a molten metal circulate desirably and properly in the above-mentioned manner. However, the number and the arrangement of these elements can be selected as desired.

In any of the above-described embodiments, the circulation of the heating medium can be quite desirably and properly performed, and the collection of the decomposed hydrocarbon gas can also be effectively performed.

What is claimed is:

1. In an apparatus for continuously decomposing hydrocarbon material which comprises at least one decomposition chamber to be partially filled with a liquid heat transfer medium and having an inlet means for hydrocarbon material and an outlet means for hydrocarbon decomposition products, and in which said inlet and outlet means are respectively disposed above and below the level of heat transfer medium to be contained in the decomposition chamber; and at least one heating chamber to be partially filled with a liquid heat transfer medium and having an inlet means for fuel to be burned therein and outlet means for the combustion products of said fuel, and in which said inlet and outlet means are respectively above and below the level of heat transfer medium to be contained in said heating chamber; the improvement which comprises: said decomposition and heating chambers each being provided with an overflow means adjacent the level of the heat transfer medium to be contained therein, the overflow means of each chamber being in communication with the other chamber below the level of heat transfer medium to be contained therein; whereby when the apparatus contains said heat transfer medium, introduction and decomposition of the hydro carbon material in the decomposition chamber expands the volume of said heat transfer medium therein causing it to flow into one of said overflow means and into said heating chamber, and introduction and combustion of fuel in the heating chamber heats and expands the volume of the heat transfer medium therein causing it to flow into the other overflow means and into the decomposition chamber, thus supplying heat thereto for the decomposition of said hydrocarbon material.

2. An apparatus according to claim 1 wherein said overflow means is a partition dividing each of said chambers into a gas flow compartment and a separate overflow compartment from which heat transfer medium flows to the other chamber.

References Cited UNITED STATES PATENTS 701,186 5/1902 Faulkner 48-92 1,592,861 7/1926 Leonarz 48-92 X 1,803,221 4/1931 Tyrer 48-92 UX 1,921,711 8/1933 Wangemann 48--92 X 3,480,689 11/1969 Bohrer 48-92 X 3,533,739 10/1970 Pelczarski et a1. 48--92 X FOREIGN PATENTS 226,500 8/ 1925 Great Britain.

MORRIS O. WOLK, Primary Examiner R. E. SERWIN, Assistant Examiner US. Cl. X.R.

23-277 R; 48--2l1; 196ll8; 260-679, 683 

